A dream of astrophysicists and heliophysicists who study the so-called solar corona, solar eclipses produced on demand are already a reality in Earth’s orbit. The “magic” will be done by two spacecraft from the European Space Agency (ESA).
Launched aboard a powerful Indian Space Agency (ISRO) rocket, the twin Proba-3 platforms will fly together as one, “maintaining a formation accurate to a single millimeter” states ESA on its website.
This extremely high degree of control has a specific objective: to produce artificial solar eclipses as they orbit the Earth, allowing scientists to make prolonged observations (up to six hours at a time) of the solar corona.
For now, the pair will remain together during the so-called initial commissioning, overseen by mission control at the European Center for Space Security and Education, in Redu, Belgium.
Sometime in early 2025, the satellites will separate and fly an average of 150 meters apart when they reach their destination, and align with the Sun, so that Occulter will cast a shadow over Coronagraph.
Why are eclipses so important for observing the solar corona?
Solar eclipses are considered the ideal times for scientists to study the solar corona due to a unique observation condition. By an incredible astronomical coincidence, the Moon and the Sun have approximately the same apparent size in the Earth’s sky.
An almost perfect mathematical proportion (the Sun is 400 times larger than the Moon, and is 400 times further from the Earth) makes the two celestial bodies appear to be exactly the same size when observed from the earth’s surface. This “fit” means that, during a total eclipse, the Moon completely blocks the intense brightness of the solar disk, allowing instruments and telescopes to capture details of the solar corona that are normally invisible.
Under normal conditions, the brightness of the solar disk is so intense that it completely masks the visually delicate and structurally rarefied formation of the solar corona which, during the eclipse, appears luminous and different. At this exact moment, which lasts a maximum of seven minutes, scientists examine the unique characteristics of the solar corona: its plasma structures, magnetic field lines and other phenomena linked to the dynamic behavior of the plasma and the solar magnetic field.
The importance of artificial solar eclipses
Before the invention of coronagraphs (blockers of direct light from the solar disk in telescopes) and some specialized satellites, solar eclipses were virtually the only opportunity to directly study the Sun’s outer atmosphere. Even with these technologies available, solar eclipses, which occurring two to five times a year (but not always total), they become very popular scientific events in the world.
Therefore, trying to reproduce the ideal conditions of the Moon, which, approximately 384,400 kilometers from Earth, manages to completely cover the solar disk, has become an obsession for space agencies. However, “today it is not practical to put a single 150 m long space vehicle into orbit”, jokes ESA director general Josef Aschbacher on the European space agency’s website.
But now Proba-3 can achieve this same performance using just two small, incredibly synchronized rovers. The result will create new ways of working in space, says the space engineer.
When the Proba-3 spacecraft are in the highest part of their orbits, about 60,500 kilometers from the Earth’s surface, Occulter will cast a precisely controlled shadow on the Coronagraph observation satellite, 150 m away.
The result will be the production of solar eclipses on demand. “The best way to prove that this new European technology works as expected is to generate scientific data that no one has ever seen before ”, says Aschbacher.
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This content was originally published in Twin ESA satellites will create artificial eclipses in Earth orbit on the CNN Brasil website.
Source: CNN Brasil
Charles Grill is a tech-savvy writer with over 3 years of experience in the field. He writes on a variety of technology-related topics and has a strong focus on the latest advancements in the industry. He is connected with several online news websites and is currently contributing to a technology-focused platform.
